For many years, aqueous solutions of glutaraldehyde have been used as a biocide in a number of applications. Among the most important of such applications is the use of glutaraldehyde to control sulfate reducing bacteria contaminating oil wells. In this application, glutaraldehyde in concentrations of from 10 to 50 ppm is added to injection water used for secondary oil recovery.
In the oil industry glutaraldehyde is employed as either a 25 or 50 percent aqueous solution because pure glutaraldehyde is inherently unstable and polymerizes to a hard glass on standing. Extensive deterioration is known to occur when a 50 percent aqueous glutaraldehyde solution is held at 60.degree. C. for 2 to 3 weeks, the average outdoor summer temperature of many important oil producing areas.
Aqueous glutaraldehyde solutions are also expensive to ship because of the large amount of water involved. Thus, a composition which would reduce the amount of inactive material shipped and at the same time increase the shelf-life of glutaraldehyde at higher temperatures would be highly desirable.